Shell evolution in neutron-rich Ge, Se, Kr and Sr nuclei within RHB approach

The exotic even–even isotopic chains from [Formula: see text] to [Formula: see text] are investigated by means of the relativistic Hartree–Bogoliubov (RHB) approach with the explicit Density Dependent Meson-Exchange (DD-ME2) and Density-Dependent Point-Coupling (DD-PC1) models. The classic magic number [Formula: see text] is reproduced and the new number [Formula: see text] is predicted to be a robust shell closure by analysing several calculated quantities such as: two-neutron separation energies, two-neutron shell gap, neutron pairing energy, potential energy surface and neutron single particle energies. The obtained results are compared with the predictions of finite range droplet model (FRDM) and with the available experimental data. A reasonable and satisfactory agreement between the theoretical models and experiment is established.

Pairing and (9/2)n configuration in nuclei in the 208Pb region

Excited states in low-energy spectra in nuclei near 208Pb are considered. The pure (j = 9/2)n configuration approximation with delta-force is used for ground state multiplet calculations. The multiplet splitting is determined by the pairing energy, which can be defined from the even-odd straggering of the nuclear masses. For the configurations with more than two valence nucleons, the seniority scheme is used. The results of the calculations agree with the experimental data for both stable and exotic nuclei within 0.06-6.16%. Due to simplicity and absence of the fitted parameters, the model can be easily applied for studies of nature of the excited states in a wide range of nuclei.